Gas chromatography (GC) is an example of an analytical technique that may be used to aid in the determination of the composition of a compound. The technique allows for the separation of one or more constituents or analytes in a sample. The sample may be collected and passed through a column including a stationary phase by a carrier or mobile phase. The various constituents of the sample may travel at different rates through the column due to the chemical and physical properties of the constituents as well as the interaction of the constituents with the stationary phase. As the constituents exit the column the amount of each constituent may be determined and the composition of the constituents may be identified, depending on the type and arrangement of detectors provided. A variation on the above has been developed, wherein two or more columns are provided in a series, otherwise known as GCxGC. Each column may include a different stationary phase, which may help resolve separations wherein the constituents coelute, i.e., do not separate, in one stationary phase but may separate in another stationary phase.
GC has been found to be useful in detectors for identifying various compositions, such as chemical warfare agents. Detectors have been identified that may be reasonably accurate, detect compositions at relatively low threshold concentrations and provide a high detection probability. However, the detectors may be relatively large and bulky and require a relatively high amount of power or may be relatively small and light but lack sensitivity.